1. Field of the Invention
The present invention relates to an electrostatic discharge (ESD) protection device, and in particular, to an electrostatic discharge (ESD) protection device with the ability to adjust holding voltage and trigger voltage.
2. Description of the Related Art
In conventional high voltage device processes, a holding voltage of an electrostatic discharge (ESD) protection device usually is not larger than an operation voltage (VDD) of a device. Therefore, when integrated circuit devices are operated under normal operating conditions, unwanted transients, such as current and voltage surges, result in latch-up events which damage devices. However, the conventional ESD protection device is improved to increase the holding voltage, the trigger voltage simultaneously increases. Therefore, the conventional ESD protection device with improved holding voltage still can not protect the internal circuits of the device.
Thus, an electrostatic discharge (ESD) protection device with the ability to adjust holding voltage and trigger voltage is desired to solve the aforementioned problems.